Two late headers by Brendon Santalab spared Western Sydney's blushes as the substitute striker secured an unlikely 2-1 victory for last season's A-League runners-up against a rebuilding Wellington Phoenix in Sydney tonight.

The Phoenix, who finished bottom in the 2012-13 competition, were on track to upset the Wanderers when Louis Fenton tapped in following a defensive lapse with nine minutes remaining but Santalab ensured last season's minor premiers claimed their first pre-season clash against A-League opposition.

Fenton was quickest to react when a Joel Stevens cross deflected into his path but Santalab equalised in the 85th minute before rising to head the winner past Glen Moss in the final minute of regulation.

The Phoenix under new coach Ernie Merrick had the brighter start at the dimly lit Lily Homes Stadium, though it was dangerous Western Sydney forward Kwabena Appiah who went closest to breaking the deadlock when he clipped an Aaron Mooy cross on to the bar five minutes before halftime.

Appiah was a frequent menace on the right wing and also caused anxiety in the 20th minute until Moss rushed out of his area to clear a threatening through ball.

The Phoenix had more shots on goal during an entertaining opening spell - despite an uneven surface - though most were from long range and flew well clear of Ante Covic's goal.

Fenton, Stein Huysegems, Alex Rufer and Ben Sigmund all fired high and wide as the Phoenix launched their attacks from long range.

Rufer, the 17-year-old nephew of legendary All White Wynton Rufer, looked comfortable on the ball and went closest to scoring for the visitors when he held off the challenge of Wanderers captain Michael Beauchamp before angling into the box and guiding the ball wide of Covic - and the keeper's left hand post.

New striker Carlos Hernandez had limited opportunities and a couple of neat touches indicated he is not quite on the same wave length as his teammates before being subbed at the break.

Of the seven trial players listed forward Hamish Watson was the only hopeful granted a start and he also sat out the second spell as Merrick introduced Justin Gulley and Joel Stevens.

Rufer and captain Ben Sigmund were also spelled early in the second half for Luke Adams and Tobias Bertsch though it was midfielder Matt Thompson's introduction that held the most interest.

The 31-year-old former Socceroo and the A-League's most capped player went close to scoring with his first touch despite being sandwiched by two defenders as he tried to back a good first impression since being released by the Melbourne Heart in April.

Two minutes later Huysegems almost silenced the Red and Black Bloc but the off balance striker poked the ball over the bar a metre out from an open goal if front of the Wanderers most vociferous supporters in the 64th, a costly lapse in the context of a close encounter.

The Phoenix continue their build-up with a friendly against Newcastle in Weston on Saturday.